Building an electric, rideable, camera dolly...need advice!

Discussion in 'The Projects Forum' started by FilmmakerG, May 30, 2014.

  1. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    Hi there electronics/electricity experts! I'm a total noob to the forum, but from what I've seen/read, you guys really know your stuff, lol! I am attempting to build an electric, rideable camera track/street dolly. I have my old treadmill frame w/motor, wheels, drive shaft, pulleys, and an 48V/25Amp, 500W electronic scooter controller. The treadmill motor is a Brushless DC, that is 110VDC, 10Amp(4200RPM duty). Will this combination of motor-controller work together, and how the heck do I wire them?? I need to be able to move at a slow creep, as well as go at a slow-to-medium pace jog(or run if possible). Any help you guys can offer would be highly appreciated!
     
  2. DickCappels

    Moderator

    Aug 21, 2008
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    It seems unlikely that you will be able to drive the motor with the fully 100VDC from a 48V controller, but it might work up to the output capability of the controller.

    Can you post any details about the controller and/or the motor?

    With more detailed information, you have a better chance of obtaining a more detailed answer.
     
  3. MrChips

    Moderator

    Oct 2, 2009
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    Where's the joke?:D
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
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    This is just not a question of whether the motor will work and what it will take, there is all the mechanical design and this of course will impinge on whether the motor and available voltage is up to it.
    IOW the mechanical design in this case is going to be constructed around the electrical components, it is usually the other way around.
    Mechanical Stuff -> electrical Stuff :)
    Max.
     
  5. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    The Controller is very similar to this one - http://www.ebay.com/itm/48V-500W-El...arts-Motor-Controller-Brushless-/280912826020
    Here's a pic of what I have for mechanicals w/motor and controller. Nothing is connected, which is why I'm hoping you guys can give me some guidance, lol!
     
  6. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    I just posted a few pics of the rig, if you want to have a gander? I have done nothing with steering yet, as that is the least of my concern at this point? I just want to know if this is a worthy pursuit?
     
    Last edited: Jun 1, 2014
  7. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    Also, I did have to move the motor from the original position, so the drive shaft pulley needs to move over as well...
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Again it depends on the mechanics, the motor requirement will depend on the torque required to move the dolly at its point of attachment.
    And also indicate what if any reduction is required.
    Looking at your present setup, I would think you are going to need more reduction, also it is preferable to remove the flywheel, it is generally not needed for this application. it will also be easier on the motor.
    If you do remove it, many are threaded on, and some with LH thread.
    In any case, leaving it on it may come unscrewed if you reverse the dolly.

    The motor is labeled CW direction, so most likely has a threaded flywheel.
    Max.
     
    Last edited: Jun 1, 2014
  9. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    When you say reduction, what are you referring to? Also, the flywheel isn't threaded, but rather keyed, with a decent sized set screw. I read somewhere that leaving the flywheel in place helped for a smoother kinetic energy transfer on start, to prevent jerkiness?
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The distance traveled per revolution of the motor.

    This also requires energy from motor both stopping and starting and delays response, you presumably can control the response from the controller/throttle control?
    With a T.M. you do not require variable response, just very slow start and stop, hence the flywheel.
    Max.
     
  11. MaxHeadRoom

    Expert

    Jul 18, 2013
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    If the label CW is not due to the flywheel being threaded, then you should check for offset brushes on the motor, some T.M. motors had this feature to improve performance in one direction.
    Max.
     
  12. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    For filming, I would need a slow, smooth start, and slow stop, at least when shooting in what I'll call "track" mode. Otherwise, I'd also like to be able to drive it down a pathway, at a decent clip (medium pace jog?).
     
  13. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Then if you still intend using the flywheel it is more important than ever that a suitable travel to motor rev ratio is observed, (reduction).
    Max.
     
    Last edited: Jun 2, 2014
  14. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    Any idea how I should proceed with wiring the controller to the motor, at least to be able to test it? The motor has two leads, black and red, the controller has black and red leads, labeled "power". Other than that, I'm at a loss, lol?
     
  15. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    I appreciate your feedback immensely, but can you spoon-feed me a bit? When you say " travel to motor rev ratio", what does that refer to? The motor has(if I'm reading correctly?) a top rev of 4200rpm. Is that at all voltages applied, whether 12,24, or 48?
     
  16. MaxHeadRoom

    Expert

    Jul 18, 2013
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    One way of determining it at present if the motor and belts are in place, is to mark the motor pulley and one of the driven wheels, push or rotate the wheel and count the motor turns for one rev of the trolley wheel.
    The max. motor rpm is relative to applied voltage, the 4200rpm will apply to the motor rated voltage on the label, anything else will be pro-rated.
    The motor Red & Black go to the motor output of the drive, the rest should be in the instructions, if there are any?
    I see that there is a Tach input, and you should also have a digital tach on the motor, but how compatible these are with the drive would have to be checked further.
    If you can use the existing Tach it would be an asset for control.
    Max.
     
  17. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    Ok, so I marked the drive wheel and motor pulley as instructed, and turned them. It appears that the rotation ratio is something like 2.3 to 1 (motor pulley rotations to wheel rotation?).

    As for wiring, the instructions are somewhat vague? I mean to say that the motor has only two leads (red and black) and the controller has multiple leads that somehow are supposed to connect to these two? For instance, there are yellow, blue, and green phase wires coming from the controller, as well as red/black power wires, and then there the five hall wires(red, black, green, yellow and blue)?
     
  18. ronv

    AAC Fanatic!

    Nov 12, 2008
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  19. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    Actually, it is a brushless, permanent magnet motor from a treadmill. I posted a couple of pictures earlier in this thread, have a look-see.
     
  20. FilmmakerG

    Thread Starter New Member

    May 30, 2014
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    Alright, perhaps I'm eating crow here. It could very well be a brushed motor after all...I'll investigate further.
     
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